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-rw-r--r--net/sunrpc/clnt.c147
1 files changed, 124 insertions, 23 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 77479606a971..759b78b056a7 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -25,6 +25,7 @@
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/slab.h>
+#include <linux/rcupdate.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>
#include <linux/in.h>
@@ -264,6 +265,26 @@ void rpc_clients_notifier_unregister(void)
return rpc_pipefs_notifier_unregister(&rpc_clients_block);
}
+static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt,
+ const struct rpc_timeout *timeout)
+{
+ struct rpc_xprt *old;
+
+ spin_lock(&clnt->cl_lock);
+ old = rcu_dereference_protected(clnt->cl_xprt,
+ lockdep_is_held(&clnt->cl_lock));
+
+ if (!xprt_bound(xprt))
+ clnt->cl_autobind = 1;
+
+ clnt->cl_timeout = timeout;
+ rcu_assign_pointer(clnt->cl_xprt, xprt);
+ spin_unlock(&clnt->cl_lock);
+
+ return old;
+}
+
static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
{
clnt->cl_nodelen = strlen(nodename);
@@ -272,12 +293,13 @@ static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
}
-static int rpc_client_register(const struct rpc_create_args *args,
- struct rpc_clnt *clnt)
+static int rpc_client_register(struct rpc_clnt *clnt,
+ rpc_authflavor_t pseudoflavor,
+ const char *client_name)
{
struct rpc_auth_create_args auth_args = {
- .pseudoflavor = args->authflavor,
- .target_name = args->client_name,
+ .pseudoflavor = pseudoflavor,
+ .target_name = client_name,
};
struct rpc_auth *auth;
struct net *net = rpc_net_ns(clnt);
@@ -298,7 +320,7 @@ static int rpc_client_register(const struct rpc_create_args *args,
auth = rpcauth_create(&auth_args, clnt);
if (IS_ERR(auth)) {
dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
- args->authflavor);
+ pseudoflavor);
err = PTR_ERR(auth);
goto err_auth;
}
@@ -337,7 +359,8 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
{
const struct rpc_program *program = args->program;
const struct rpc_version *version;
- struct rpc_clnt *clnt = NULL;
+ struct rpc_clnt *clnt = NULL;
+ const struct rpc_timeout *timeout;
int err;
/* sanity check the name before trying to print it */
@@ -365,7 +388,6 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
if (err)
goto out_no_clid;
- rcu_assign_pointer(clnt->cl_xprt, xprt);
clnt->cl_procinfo = version->procs;
clnt->cl_maxproc = version->nrprocs;
clnt->cl_prog = args->prognumber ? : program->number;
@@ -380,16 +402,15 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
INIT_LIST_HEAD(&clnt->cl_tasks);
spin_lock_init(&clnt->cl_lock);
- if (!xprt_bound(xprt))
- clnt->cl_autobind = 1;
-
- clnt->cl_timeout = xprt->timeout;
+ timeout = xprt->timeout;
if (args->timeout != NULL) {
memcpy(&clnt->cl_timeout_default, args->timeout,
sizeof(clnt->cl_timeout_default));
- clnt->cl_timeout = &clnt->cl_timeout_default;
+ timeout = &clnt->cl_timeout_default;
}
+ rpc_clnt_set_transport(clnt, xprt, timeout);
+
clnt->cl_rtt = &clnt->cl_rtt_default;
rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
@@ -398,7 +419,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
/* save the nodename */
rpc_clnt_set_nodename(clnt, utsname()->nodename);
- err = rpc_client_register(args, clnt);
+ err = rpc_client_register(clnt, args->authflavor, args->client_name);
if (err)
goto out_no_path;
if (parent)
@@ -600,6 +621,80 @@ rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
}
EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
+/**
+ * rpc_switch_client_transport: switch the RPC transport on the fly
+ * @clnt: pointer to a struct rpc_clnt
+ * @args: pointer to the new transport arguments
+ * @timeout: pointer to the new timeout parameters
+ *
+ * This function allows the caller to switch the RPC transport for the
+ * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
+ * server, for instance. It assumes that the caller has ensured that
+ * there are no active RPC tasks by using some form of locking.
+ *
+ * Returns zero if "clnt" is now using the new xprt. Otherwise a
+ * negative errno is returned, and "clnt" continues to use the old
+ * xprt.
+ */
+int rpc_switch_client_transport(struct rpc_clnt *clnt,
+ struct xprt_create *args,
+ const struct rpc_timeout *timeout)
+{
+ const struct rpc_timeout *old_timeo;
+ rpc_authflavor_t pseudoflavor;
+ struct rpc_xprt *xprt, *old;
+ struct rpc_clnt *parent;
+ int err;
+
+ xprt = xprt_create_transport(args);
+ if (IS_ERR(xprt)) {
+ dprintk("RPC: failed to create new xprt for clnt %p\n",
+ clnt);
+ return PTR_ERR(xprt);
+ }
+
+ pseudoflavor = clnt->cl_auth->au_flavor;
+
+ old_timeo = clnt->cl_timeout;
+ old = rpc_clnt_set_transport(clnt, xprt, timeout);
+
+ rpc_unregister_client(clnt);
+ __rpc_clnt_remove_pipedir(clnt);
+
+ /*
+ * A new transport was created. "clnt" therefore
+ * becomes the root of a new cl_parent tree. clnt's
+ * children, if it has any, still point to the old xprt.
+ */
+ parent = clnt->cl_parent;
+ clnt->cl_parent = clnt;
+
+ /*
+ * The old rpc_auth cache cannot be re-used. GSS
+ * contexts in particular are between a single
+ * client and server.
+ */
+ err = rpc_client_register(clnt, pseudoflavor, NULL);
+ if (err)
+ goto out_revert;
+
+ synchronize_rcu();
+ if (parent != clnt)
+ rpc_release_client(parent);
+ xprt_put(old);
+ dprintk("RPC: replaced xprt for clnt %p\n", clnt);
+ return 0;
+
+out_revert:
+ rpc_clnt_set_transport(clnt, old, old_timeo);
+ clnt->cl_parent = parent;
+ rpc_client_register(clnt, pseudoflavor, NULL);
+ xprt_put(xprt);
+ dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
+ return err;
+}
+EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
+
/*
* Kill all tasks for the given client.
* XXX: kill their descendants as well?
@@ -772,6 +867,8 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
atomic_inc(&clnt->cl_count);
if (clnt->cl_softrtry)
task->tk_flags |= RPC_TASK_SOFT;
+ if (clnt->cl_noretranstimeo)
+ task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
if (sk_memalloc_socks()) {
struct rpc_xprt *xprt;
@@ -1690,6 +1787,7 @@ call_connect_status(struct rpc_task *task)
dprint_status(task);
trace_rpc_connect_status(task, status);
+ task->tk_status = 0;
switch (status) {
/* if soft mounted, test if we've timed out */
case -ETIMEDOUT:
@@ -1698,12 +1796,14 @@ call_connect_status(struct rpc_task *task)
case -ECONNREFUSED:
case -ECONNRESET:
case -ENETUNREACH:
+ /* retry with existing socket, after a delay */
+ rpc_delay(task, 3*HZ);
if (RPC_IS_SOFTCONN(task))
break;
- /* retry with existing socket, after a delay */
- case 0:
case -EAGAIN:
- task->tk_status = 0;
+ task->tk_action = call_bind;
+ return;
+ case 0:
clnt->cl_stats->netreconn++;
task->tk_action = call_transmit;
return;
@@ -1717,13 +1817,14 @@ call_connect_status(struct rpc_task *task)
static void
call_transmit(struct rpc_task *task)
{
+ int is_retrans = RPC_WAS_SENT(task);
+
dprint_status(task);
task->tk_action = call_status;
if (task->tk_status < 0)
return;
- task->tk_status = xprt_prepare_transmit(task);
- if (task->tk_status != 0)
+ if (!xprt_prepare_transmit(task))
return;
task->tk_action = call_transmit_status;
/* Encode here so that rpcsec_gss can use correct sequence number. */
@@ -1742,6 +1843,8 @@ call_transmit(struct rpc_task *task)
xprt_transmit(task);
if (task->tk_status < 0)
return;
+ if (is_retrans)
+ task->tk_client->cl_stats->rpcretrans++;
/*
* On success, ensure that we call xprt_end_transmit() before sleeping
* in order to allow access to the socket to other RPC requests.
@@ -1811,8 +1914,7 @@ call_bc_transmit(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
- task->tk_status = xprt_prepare_transmit(task);
- if (task->tk_status == -EAGAIN) {
+ if (!xprt_prepare_transmit(task)) {
/*
* Could not reserve the transport. Try again after the
* transport is released.
@@ -1900,7 +2002,8 @@ call_status(struct rpc_task *task)
rpc_delay(task, 3*HZ);
case -ETIMEDOUT:
task->tk_action = call_timeout;
- if (task->tk_client->cl_discrtry)
+ if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
+ && task->tk_client->cl_discrtry)
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
break;
@@ -1982,7 +2085,6 @@ call_timeout(struct rpc_task *task)
rpcauth_invalcred(task);
retry:
- clnt->cl_stats->rpcretrans++;
task->tk_action = call_bind;
task->tk_status = 0;
}
@@ -2025,7 +2127,6 @@ call_decode(struct rpc_task *task)
if (req->rq_rcv_buf.len < 12) {
if (!RPC_IS_SOFT(task)) {
task->tk_action = call_bind;
- clnt->cl_stats->rpcretrans++;
goto out_retry;
}
dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 13:50:05 +0100